skia2/gm/convex_all_line_paths.cpp
mtklein dbfd7ab108 Replace a lot of 'static const' with 'constexpr' or 'const'.
'static const' means, there must be at most one of these, and initialize it at
compile time if possible or runtime if necessary.  This leads to unexpected
code execution, and TSAN* will complain about races on the guard variables.

Generally 'constexpr' or 'const' are better choices.  Neither can cause races:
they're either intialized at compile time (constexpr) or intialized each time
independently (const).

This CL prefers constexpr where possible, and uses const where not.  It even
prefers constexpr over const where they don't make a difference... I want to have
lots of examples of constexpr for people to see and mimic.

The scoped-to-class static has nothing to do with any of this, and is not changed.

* Not yet on the bots, which use an older TSAN.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2300623005

Review-Url: https://codereview.chromium.org/2300623005
2016-09-01 11:24:54 -07:00

355 lines
11 KiB
C++

/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "gm.h"
#include "SkPathPriv.h"
static void create_ngon(int n, SkPoint* pts, SkScalar width, SkScalar height) {
float angleStep = 360.0f / n, angle = 0.0f, sin, cos;
if ((n % 2) == 1) {
angle = angleStep/2.0f;
}
for (int i = 0; i < n; ++i) {
sin = SkScalarSinCos(SkDegreesToRadians(angle), &cos);
pts[i].fX = -sin * width;
pts[i].fY = cos * height;
angle += angleStep;
}
}
namespace skiagm {
// This GM is intended to exercise Ganesh's handling of convex line-only
// paths
class ConvexLineOnlyPathsGM : public GM {
public:
ConvexLineOnlyPathsGM(bool doStrokeAndFill) : fDoStrokeAndFill(doStrokeAndFill) {
this->setBGColor(0xFFFFFFFF);
}
protected:
SkString onShortName() override {
if (fDoStrokeAndFill) {
return SkString("convex-lineonly-paths-stroke-and-fill");
}
return SkString("convex-lineonly-paths");
}
SkISize onISize() override { return SkISize::Make(kGMWidth, kGMHeight); }
bool runAsBench() const override { return true; }
static SkPath GetPath(int index, int offset, SkPath::Direction dir) {
// narrow rect
const SkPoint gPoints0[] = {
{ -1.5f, -50.0f },
{ 1.5f, -50.0f },
{ 1.5f, 50.0f },
{ -1.5f, 50.0f }
};
// narrow rect on an angle
const SkPoint gPoints1[] = {
{ -50.0f, -49.0f },
{ -49.0f, -50.0f },
{ 50.0f, 49.0f },
{ 49.0f, 50.0f }
};
// trap - narrow on top - wide on bottom
const SkPoint gPoints2[] = {
{ -10.0f, -50.0f },
{ 10.0f, -50.0f },
{ 50.0f, 50.0f },
{ -50.0f, 50.0f }
};
// wide skewed rect
const SkPoint gPoints3[] = {
{ -50.0f, -50.0f },
{ 0.0f, -50.0f },
{ 50.0f, 50.0f },
{ 0.0f, 50.0f }
};
// thin rect with colinear-ish lines
const SkPoint gPoints4[] = {
{ -6.0f, -50.0f },
{ 4.0f, -50.0f },
{ 5.0f, -25.0f },
{ 6.0f, 0.0f },
{ 5.0f, 25.0f },
{ 4.0f, 50.0f },
{ -4.0f, 50.0f }
};
// degenerate
const SkPoint gPoints5[] = {
{ -0.025f, -0.025f },
{ 0.025f, -0.025f },
{ 0.025f, 0.025f },
{ -0.025f, 0.025f }
};
// Triangle in which the first point should fuse with last
const SkPoint gPoints6[] = {
{ -20.0f, -13.0f },
{ -20.0f, -13.05f },
{ 20.0f, -13.0f },
{ 20.0f, 27.0f }
};
// thin rect with colinear lines
const SkPoint gPoints7[] = {
{ -10.0f, -50.0f },
{ 10.0f, -50.0f },
{ 10.0f, -25.0f },
{ 10.0f, 0.0f },
{ 10.0f, 25.0f },
{ 10.0f, 50.0f },
{ -10.0f, 50.0f }
};
// capped teardrop
const SkPoint gPoints8[] = {
{ 50.00f, 50.00f },
{ 0.00f, 50.00f },
{ -15.45f, 47.55f },
{ -29.39f, 40.45f },
{ -40.45f, 29.39f },
{ -47.55f, 15.45f },
{ -50.00f, 0.00f },
{ -47.55f, -15.45f },
{ -40.45f, -29.39f },
{ -29.39f, -40.45f },
{ -15.45f, -47.55f },
{ 0.00f, -50.00f },
{ 50.00f, -50.00f }
};
// teardrop
const SkPoint gPoints9[] = {
{ 4.39f, 40.45f },
{ -9.55f, 47.55f },
{ -25.00f, 50.00f },
{ -40.45f, 47.55f },
{ -54.39f, 40.45f },
{ -65.45f, 29.39f },
{ -72.55f, 15.45f },
{ -75.00f, 0.00f },
{ -72.55f, -15.45f },
{ -65.45f, -29.39f },
{ -54.39f, -40.45f },
{ -40.45f, -47.55f },
{ -25.0f, -50.0f },
{ -9.55f, -47.55f },
{ 4.39f, -40.45f },
{ 75.00f, 0.00f }
};
// clipped triangle
const SkPoint gPoints10[] = {
{ -10.0f, -50.0f },
{ 10.0f, -50.0f },
{ 50.0f, 31.0f },
{ 40.0f, 50.0f },
{ -40.0f, 50.0f },
{ -50.0f, 31.0f },
};
const SkPoint* gPoints[] = {
gPoints0, gPoints1, gPoints2, gPoints3, gPoints4, gPoints5, gPoints6,
gPoints7, gPoints8, gPoints9, gPoints10,
};
const size_t gSizes[] = {
SK_ARRAY_COUNT(gPoints0),
SK_ARRAY_COUNT(gPoints1),
SK_ARRAY_COUNT(gPoints2),
SK_ARRAY_COUNT(gPoints3),
SK_ARRAY_COUNT(gPoints4),
SK_ARRAY_COUNT(gPoints5),
SK_ARRAY_COUNT(gPoints6),
SK_ARRAY_COUNT(gPoints7),
SK_ARRAY_COUNT(gPoints8),
SK_ARRAY_COUNT(gPoints9),
SK_ARRAY_COUNT(gPoints10),
};
static_assert(SK_ARRAY_COUNT(gSizes) == SK_ARRAY_COUNT(gPoints), "array_mismatch");
SkAutoTDeleteArray<SkPoint> data(nullptr);
const SkPoint* points;
int numPts;
if (index < (int) SK_ARRAY_COUNT(gPoints)) {
// manually specified
points = gPoints[index];
numPts = (int) gSizes[index];
} else {
// procedurally generated
SkScalar width = kMaxPathHeight/2;
SkScalar height = kMaxPathHeight/2;
switch (index-SK_ARRAY_COUNT(gPoints)) {
case 0:
numPts = 3;
break;
case 1:
numPts = 4;
break;
case 2:
numPts = 5;
break;
case 3: // squashed pentagon
numPts = 5;
width = kMaxPathHeight/5;
break;
case 4:
numPts = 6;
break;
case 5:
numPts = 8;
break;
case 6: // squashed octogon
numPts = 8;
width = kMaxPathHeight/5;
break;
case 7:
numPts = 20;
break;
case 8:
numPts = 100;
break;
default:
numPts = 3;
break;
}
data.reset(new SkPoint[numPts]);
create_ngon(numPts, data.get(), width, height);
points = data.get();
}
SkPath path;
if (SkPath::kCW_Direction == dir) {
path.moveTo(points[0]);
for (int i = 1; i < numPts; ++i) {
path.lineTo(points[i]);
}
} else {
path.moveTo(points[numPts-1]);
for (int i = numPts-2; i >= 0; --i) {
path.lineTo(points[i]);
}
}
path.close();
#ifdef SK_DEBUG
// Each path this method returns should be convex, only composed of
// lines, wound the right direction, and short enough to fit in one
// of the GMs rows.
SkASSERT(path.isConvex());
SkASSERT(SkPath::kLine_SegmentMask == path.getSegmentMasks());
SkPathPriv::FirstDirection actualDir;
SkASSERT(SkPathPriv::CheapComputeFirstDirection(path, &actualDir));
SkASSERT(SkPathPriv::AsFirstDirection(dir) == actualDir);
SkRect bounds = path.getBounds();
SkASSERT(SkScalarNearlyEqual(bounds.centerX(), 0.0f));
SkASSERT(bounds.height() <= kMaxPathHeight);
#endif
return path;
}
// Draw a single path several times, shrinking it, flipping its direction
// and changing its start vertex each time.
void drawPath(SkCanvas* canvas, int index, SkPoint* offset) {
SkPoint center;
{
SkPath path = GetPath(index, 0, SkPath::kCW_Direction);
if (offset->fX+path.getBounds().width() > kGMWidth) {
offset->fX = 0;
offset->fY += kMaxPathHeight;
if (fDoStrokeAndFill) {
offset->fX += kStrokeWidth / 2.0f;
offset->fY += kStrokeWidth / 2.0f;
}
}
center = { offset->fX + SkScalarHalf(path.getBounds().width()), offset->fY};
offset->fX += path.getBounds().width();
if (fDoStrokeAndFill) {
offset->fX += kStrokeWidth;
}
}
const SkColor colors[2] = { SK_ColorBLACK, SK_ColorWHITE };
const SkPath::Direction dirs[2] = { SkPath::kCW_Direction, SkPath::kCCW_Direction };
const float scales[] = { 1.0f, 0.75f, 0.5f, 0.25f, 0.1f, 0.01f, 0.001f };
const SkPaint::Join joins[3] = { SkPaint::kRound_Join,
SkPaint::kBevel_Join,
SkPaint::kMiter_Join };
SkPaint paint;
paint.setAntiAlias(true);
for (size_t i = 0; i < SK_ARRAY_COUNT(scales); ++i) {
SkPath path = GetPath(index, (int) i, dirs[i%2]);
if (fDoStrokeAndFill) {
paint.setStyle(SkPaint::kStrokeAndFill_Style);
paint.setStrokeJoin(joins[i%3]);
paint.setStrokeWidth(SkIntToScalar(kStrokeWidth));
}
canvas->save();
canvas->translate(center.fX, center.fY);
canvas->scale(scales[i], scales[i]);
paint.setColor(colors[i%2]);
canvas->drawPath(path, paint);
canvas->restore();
}
}
void onDraw(SkCanvas* canvas) override {
// the right edge of the last drawn path
SkPoint offset = { 0, SkScalarHalf(kMaxPathHeight) };
if (fDoStrokeAndFill) {
offset.fX += kStrokeWidth / 2.0f;
offset.fY += kStrokeWidth / 2.0f;
}
for (int i = 0; i < kNumPaths; ++i) {
this->drawPath(canvas, i, &offset);
}
// Repro for crbug.com/472723 (Missing AA on portions of graphic with GPU rasterization)
{
canvas->translate(356.0f, 50.0f);
SkPaint p;
p.setAntiAlias(true);
if (fDoStrokeAndFill) {
p.setStyle(SkPaint::kStrokeAndFill_Style);
p.setStrokeJoin(SkPaint::kMiter_Join);
p.setStrokeWidth(SkIntToScalar(kStrokeWidth));
}
SkPath p1;
p1.moveTo(60.8522949f, 364.671021f);
p1.lineTo(59.4380493f, 364.671021f);
p1.lineTo(385.414276f, 690.647217f);
p1.lineTo(386.121399f, 689.940125f);
canvas->drawPath(p1, p);
}
}
private:
static constexpr int kStrokeWidth = 10;
static constexpr int kNumPaths = 20;
static constexpr int kMaxPathHeight = 100;
static constexpr int kGMWidth = 512;
static constexpr int kGMHeight = 512;
bool fDoStrokeAndFill;
typedef GM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
DEF_GM(return new ConvexLineOnlyPathsGM(false);)
DEF_GM(return new ConvexLineOnlyPathsGM(true);)
}